KR20150118098A - Infinitely Vertically Adjustable Intervertebral Fusion Implant - Google Patents

Abstract

The present application relates to an intervertebral fusion implant for fusing two adjacent vertebrae, including a base piece (2), a cover piece (3) and an expansion device. The base piece 2 and the cover piece 3 are connected by an externally hinged rocker 4 located between them and the expansion device is an expansion clamp 6,6 'on the rocker and the pushing device 5 ) Is provided for the expansion clamp. The expansion clamp allows the rocker to be elevated so that the implant is vertically expanded. Since the rocker is hinged from the outside, a large vertical movement path is available. Also, the frictional force of the expansion clamp prevents unwanted return movement.

Description

[0001] Infinitely Vertically Adjustable Intervertebral Fusion Implant [0002]

The present invention relates to an implant for fusing two adjacent vertebrae, including a base piece and a cover piece and an expansion means.

Spinal discs undergo degeneration as a result of wear or pathological changes. If conservative treatment by drugs and / or physical therapy is not effective, surgical treatment is sometimes recommended. In this connection, it is known that movable or floating implants are inserted into the intervertebral space including the degenerated intervertebral disc. These implants take over the supporting function of the degenerated discs and restore a stable support between adjacent vertebrae. Floating implants are also called "fusion implants".

A variety of surgical techniques for implanting fusion implants are known. Traditional surgical techniques avoid the risk of damaging the spinal cord in the spinal column, including the abdominal access route. However, this advantage is obtained as a cost of a very long access route through the abdominal cavity or thoracic cavity of the patient. Since this can lead to complications, an alternative approach route has been established from the dorsal direction. The latter provides the advantage of a short route, but there is a risk of collision with or damage to the spinal cord. To minimize this risk, surgery is usually performed by minimally invasive surgery. This type of approach, either directly or from the lateral direction, is known as PLIF (Posterior Lumbar Intervertebral Fusion) or TLIF (Transforaminal Lumbar Interbody Fusion), wherein the intervertebral discs Or from the lateral direction. Because of the small transverse incisions used in minimally invasive surgical approaches, the size of the fusion implants is of course largely limited here.

For treatment with PLIF or TLIF techniques, very small fusion implants are known. They offer the advantage of being able to be implanted by minimally invasive surgery due to its small size. However, the inherent disadvantage of its small size is that the support function is limited and sometimes inappropriate due to the small dimensions. Larger sizes of fusion implants improve supportability, but this is unrealistic due to limitations of minimally invasive surgery.

The present invention is directed to improving the fusion implants of the type mentioned at the outset, so as to still achieve an improved support effect even in the case of large intervertebral spaces, while still having a small approaching cross-section as is common for minimally invasive surgery Ready.

The solution according to the invention lies in the characterizing part of the independent claim. The subject matter of the dependent claims relates to advantageous improvements.

According to the present invention, in an intervertebral fusion implant for fusing two adjacent vertebrae comprising a base piece, a base piece and a cover piece and an expansion means, according to the present invention, a connection is made by a rocker positioned between the base piece and the cover piece, And the inflation means is an inflator clip on the rocker and a drive means is provided for the inflator clip.

The present invention is based on the concept of lifting a rocker coupled externally by a drive means and the inflator clip acting as a transmission member in this case. By raising the rocker, the cover piece and base piece move away to expand the intervertebral fusion implant in terms of height. As a result of the outer engagement of the rocker, a relatively large lift movement is therefore available. In addition to the relatively large upward movement, the delivery of the inflator clip onto the rocker provides the advantage of more frictional points that generate an available blocking effect by using the inflator clip as the transmitting member. This counteracts the risk of accidental return, or height reduction.

Intervertebral fusion implants configured in accordance with the present invention also provide a continuously adjustable advantage. Therefore, the implant can be particularly fine-tuned for each anatomical condition of the patient. An additional advantage consists in fact that the implant can not be returned in principle. That is, when the drive means is operated in the opposite direction, the expansion is reduced and the height of the implant is reduced. Sometimes this is a significant advantage, especially for test purposes, as well as for implantation in anatomically challenging areas.

Two inflator clips located opposite each other are conveniently provided. This provides the advantage of the application of a larger, symmetrical force from both sides. As a result of application of forces from both sides, the risk of tilting between the base piece and the cover piece during lift-up is offset.

A convenient embodiment of the drive means is a shrinkage element. In this case, the inflator clip may be formed by the second inflator clip and is pulled against the counter-bearing which is open during expansion. This is particularly convenient in terms of mechanics and enables a linear embodiment with considerable advantages over its compactness in the context of the installation space aspect. A particularly convenient embodiment is the use of a threaded spindle as an actuator for the drive means. This allows for high power transfer while having low installation space requirements at the same time. In addition, the threaded spindle offers the advantage of inherent self-retention, and there is no accidental return of the expansion achieved as a result. However, on the other hand, the threaded spindle allows reduction of expansion in a planned manner by operation in the opposite direction.

The rocker preferably consists of an integral embodiment with its hinges. This reduces the number of components and simplifies fabrication. Integral fabrication also always ensures that parts aligned to one another are used, and thus, unlike in the case of separate parts, there can be no misalignment due to improper tolerances. In this connection, it is particularly convenient for the rocker to have an integral design with the base piece and / or the cover piece.

Embodiments with dual lockers are convenient. This increases the adjustment range, more precisely the maximum expansion, with only a little additional complexity.

In order to actuate the drive means, an actuating connector is conveniently provided on the rear end face. This arrangement on the end face provides the advantage of being able to reach the working connector through the same minimally invasive access where the intervertebral fusion implant according to the invention is inserted. Therefore, it is easily accessible even in the case of re-operation. Embodiments of working connectors as screw couplings are particularly convenient. Here, this may in particular be a nut attached to the operating spindle.

At least one through-hole is preferably formed in the cover surface and / or the base surface. What this allows is that the bone material can grow into the interior region of the implant in an improved manner. As a result, the required convergence of two adjacent vertebral bodies is accelerated.

The invention will be described in more detail below on the basis of two exemplary embodiments, with reference to the accompanying drawings.

Figure 1 shows a schematic view of an intervertebral fusion implant according to a first exemplary embodiment, implanted on a vertebral body.
Figure 2 shows a perspective view of the first exemplary embodiment at an assembled position.
Figure 3 shows a perspective view of a first exemplary embodiment in an extended position, in an operative position;
Figure 4 shows a perspective view of a second exemplary embodiment at an assembled position.
Figure 5 shows a perspective view of a second exemplary embodiment in an extended position, in an operative position.

An intervertebral fusion implant, generally indicated by reference numeral 1, is provided to be implanted in the intervertebral space 91 between two immediately adjacent vertebrae 9, 9 '. Within the physiologically intact spinal column, an intervertebral disc 90 is located in the intervertebral space between the vertebrae. These discs may suffer degeneration as a result of disease or abrasion, and as a result should be at least partially resected. The intervertebral fusion implant 1 is inserted into the intervertebral space 91 in order to achieve sufficient support of the intervertebral space 91 and prevent the collapse of the spinal column despite the disappearance of the intervertebral disc material. This provides supportive action to facilitate fusion of two adjacent vertebrae 9, 9 'in a natural manner through bone growth.

A first exemplary embodiment of an intervertebral fusion implant according to the present invention, shown in Figures 2 and 3 and indicated generally by the numeral 1, comprises a base piece 2 and a cover piece 3, (4). Here, the rocker 4 is integrally connected to the base piece 2 and the cover piece 3 by two hinges 42, 43 at the outer end of the hinge. The hinges 42 and 43 are arranged at the opposite ends of the rocker 4 and also at the sides of the base piece 2 and the cover piece 3 positioned opposite to each other. In the illustrated exemplary embodiment, the hinge 42 connecting the rocker 4 to the base piece 2 is located at the front end (on the right side of the view of Figures 2 and 3) The hinge 43 connecting to the piece 3 is located at the rear end. Overall, this result is a Z-shaped type for the first exemplary embodiment.

The perforations 22 are arranged in the base piece 2. [ This connects the space under the base piece 2 with the space between the base piece 2 and the locker 4 or the cover piece 3. [

An inflator clip 6 was inserted between the rocker 4 and the cover piece 3 into the interspace opened in the forward direction. Which has a guide piece 60 that slides into the space between the rocker 4 and the cover piece 3 in the manner of the tongue. 2, the free end thereof is a certain distance from the hinge 43 between the cover piece 3 and the locker 4. In the assembled position as shown in Fig. The guide piece 60 is integrally connected to the holding loop 61 at the other end thereof. The retaining loops have a U-shaped section that narrows towards the top, one wing of U being held on the cover piece 3 and the other wing of U being supported on the rocker 4 within the area of the hinge 42. The two wings are connected by a base piece of a U-shaped loop 61, which forms the front end of the inflator clip 6. There is provided an opening 62 for passing the thread spindle 70 therethrough. In this case, the threaded spindle 70 extends through the inner space of the U-shaped retaining loop 61, in the assembled position, from the rear end through the locker 4, parallel to the guide piece 60, And ends in the region of the opening 62.

The size of the loop 61 is dimensioned such that the counter bearing 71 for the threaded spindle 70 is retained therein. In the illustrated exemplary embodiment, the counter bearing 71 is configured as a cylindrical body having a through bore with a female thread complementary to the threaded spindle 70 across the cylindrical axis.

In the illustrated exemplary embodiment, a second inflator clip 6 'is provided which is inserted in a complementary manner in the space between the base piece 2 and the locker 4, which is open in the rearward direction. It has a design similar to the U-shaped loop 61 'with the guide piece 60' and an opening 62 'facing the end. The other end of the threaded spindle 70 is pushed through this opening and a welded nut-shaped threaded coupling 73 is positioned at the rear end of the threaded spindle 70 located outside the U-shaped loop 61 ' do.

The intervertebral fusion implant according to the present invention is inserted through its minimally invasive approach into its intended position within the intervertebral space 91 in the illustrated assembly position (see FIG. 2). After insertion, it expands to reach the upper cover plate 92 of the lower adjacent vertebrae at its cover piece 2, and at its cover piece 3, the lower cover plate of the upper adjacent vertebra 9 ' (93).

Here, the intervertebral fusion implant is operated for expansion purposes as follows: a properly aligned wrench is applied to the nut, which is the threaded connector 73. [ By rotating the nut together with the threaded spindle 70 welded thereto the shrinking means formed by the threaded spindle 70 and the counter bearing 71 and the nut 73 are contracted and the inflator clip 6 is rotated by the locker 4, And the cover piece (3). The corresponding state is applied to the inflator clip 6 'arranged opposite thereto. By pulling the inflator clips 6, 6 'into their respective spaces, the U-shaped loops 61, 61' are fastened by their tapered wings to the hinge (not shown) of the cover piece 3 and the inflator clip 6 42 and the outer end of the hinge 43 relative to the base piece 2 and the inflator clip 6 'so that the space between the rocker and the base piece 2 or the cover piece 3, respectively, Is expanded.

As a result, the implant is expanded in height, i.e., the distance between the base piece 2 and the cover piece 3 increases. Such an expanded condition as provided for retention of the implant is shown in Fig. This is called the working position. It is possible to confirm that the inflator clips 6 and 6 'pulled inward by the drive means 7 extend the space between them and thus cause a distance increase between the base piece 2 and the cover piece 3. [

It should be noted that this extension is continuous and can be reversed completely or partially at any time by returning the screw spindle 70. It should also be noted that the guaranteed arrangement of the threaded spindle 70 with the counter bearing 71 having the through bore with female threads causes self retention. Thus, there can be no reduction in distance without clear and proper operation by the physician.

Figures 4 and 5 illustrate a second exemplary embodiment. Similar parts are provided with the same reference numerals as in the first exemplary embodiment.

A substantial difference from the first exemplary embodiment lies in the fact that the rocker is embodied as a double locker 4, 4 'with an additional hinge 44 between the two lockers 4, 4'. As a result, the Z-shape of the first exemplary embodiment extends to the type of M-shape. Here, the two interspaces on the front side, i.e. the space between the cover piece 3 and the rocker 4, first as in the first exemplary embodiment, and now also between the base piece 2 and the additional locker 4 '). The corresponding front inflator clip 6 now has two guide pieces 60 and 60 'and the further guide piece 60' is located between the base piece 2 and the further locker 4 ' , And is deformed in such a manner that it engages in the newly generated interspace opened in the forward direction.

Shaped screw 71 'arranged in the opening on the base portion of the U-shaped loop 61 "serves as a counter bearing. The two inflator clips 6 ', 6 ' are pulled into the interspace, resulting in the inflated interspace and the cover piece 3 moving away from the base piece 2. [

Claims (10)

An intervertebral fusion implant for fusing two adjacent vertebrae including a base piece (2), a cover piece (3) and an expansion means,
The base piece 2 and the cover piece 3 are connected by a rocker 4 positioned between them and joined externally and the expansion means is an inflator clip 6 on the rocker and the drive means 5 is connected to the inflator clip 4. [ (6). ≪ RTI ID = 0.0 > 11. < / RTI > 2. Intervertebral fusion implant according to claim 1, characterized in that at least two inflator clips (6, 6 ') are provided opposite to each other. The intervertebral fusion implant according to claim 1 or 2, characterized in that the drive means (5) is configured as a contraction element. 4. An intervertebral fusion implant according to any one of claims 1 to 3, characterized in that the threaded spindle (70) forms an actuator for the drive means (5). 5. An intervertebral fusion implant according to any one of claims 1 to 4, characterized in that the rocker (4) has a hinge (42, 43) with an integral design. 6. An intervertebral fusion implant according to claim 5, characterized in that the rocker (4) has an integral design with the base piece (2) and / or the cover piece (3). 7. An intervertebral fusion implant according to any one of claims 1 to 6, characterized in that the rocker (4) is configured as a double locker (4 '). 8. An intervertebral fusion implant according to any one of claims 1 to 7, characterized in that an actuating connector for the drive means is arranged on the rear end face. 9. An intervertebral fusion implant according to claim 8, wherein the actuating connector is configured as a threaded coupling (73). 10. An intervertebral fusion implant according to any one of claims 1 to 9, characterized in that at least one through hole (22) is formed in its cover piece (2) and / or base piece (3).

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